Cow gestation calculator.
Find out when a cow is due to calve. Enter the breeding date and the calculator estimates the calving date from the average bovine gestation, with the earliest and latest dates.
Breeding date
LiveCow gestation lasts about 279 to 287 days, averaging near 283. The calving date is the breeding date plus the average gestation; the range gives the earliest and latest.
Estimated calving date
Mar 11, 2027
based on average gestation
An estimate based on average bovine gestation; breed and individual cows vary. Not veterinary advice. Calculations run in your browser; nothing you enter is stored.
How it works
Counting from breeding
A cow’s gestation lasts about 279 to 287 days from breeding, averaging close to 283 days, a little over nine months. The calculator adds the average gestation to the breeding or service date to estimate the calving date, and the range gives the earliest and latest you should expect the calf.
Gestation varies by breed: dairy breeds like Holstein tend toward the shorter end, while many beef breeds run a few days longer. Bull calves are often carried slightly longer than heifers.
Reference
Gestation by animal.
Typical pregnancy lengths for cattle and other common animals, for comparison.
| Animal | Gestation |
|---|---|
| Cat | 63 to 67 days |
| Dog | 58 to 68 days |
| Cow | 279 to 287 days |
| Goat | 145 to 155 days |
| Sheep | 144 to 152 days |
| Horse | 320 to 370 days |
The full guide
The complete guide to cow gestation.
How long cattle carry, what changes the length, and how to plan around calving.
How long is a cow pregnant?
Bovine gestation averages about 283 days, roughly nine months and one week, with a normal range of 279 to 287 days. Counting from the breeding or artificial-insemination date gives the most reliable estimate of when the calf is due.
Because the breeding date is usually known on a managed farm, the calving window can be predicted fairly closely.
What changes the length
Breed is the biggest factor: dairy breeds such as Holstein and Jersey tend toward the shorter end of the range, while beef breeds like Charolais can run several days longer. The calf’s sex matters too, with bull calves often carried a little longer.
Twins and the dam’s age and condition can also shift the date slightly.
Planning around calving
Knowing the due date lets you plan the dry-off period for dairy cows, prepare a clean calving area, and be on hand for the birth. Most cows calve unassisted, but having the window helps you watch the right animals at the right time.
Move close-to-calving cows to a clean, sheltered area a week or two ahead.
When to get help
Call a vet if a cow goes well past 287 to 290 days, if she is in active labour for more than a couple of hours without progress, or if you see signs of distress or abnormal presentation. Early help greatly improves outcomes.
This tool is for planning only and does not replace veterinary care.
The formula
Date plus
gestation.
A cow’s calving date is the breeding date plus about 283 days, with calves normally arriving between 279 and 287 days.
Goat gestation ›# Cow calving date
due = breeding_date + gestation
cow gestation = 279 to 287 days
# average 283 days
breeding + 283 daysQuestions
Cow gestation questions.
How long is a cow pregnant?
+
About 279 to 287 days from breeding, averaging around 283 days, a little over nine months. The calculator uses this to estimate the calving date.
How do I calculate a cow’s calving date?
+
Add about 283 days to the breeding or service date. Enter that date above and the calculator gives the estimated calving date plus the earliest and latest.
Does breed change the gestation length?
+
Yes. Dairy breeds tend toward the shorter end of 279 to 287 days, while many beef breeds run a few days longer. Bull calves are often carried slightly longer.
When should I call a vet?
+
Call a vet if a cow goes well past 287 to 290 days, labours more than a couple of hours without progress, or shows distress. Early help improves outcomes.
Is this cow gestation calculator free?
+
Yes. It is completely free with no sign-up, and every calculation runs locally in your browser, so nothing you enter is stored or sent anywhere.
About the developer
Jean Borg
Jean builds and maintains every calculator on freecalculators.pro from Malta, with a focus on tools that are fast, free and show their working. The cow gestation calculator estimates a calving date from average bovine gestation and is for planning, not veterinary advice.